Apparatus for the distillation of high-boiling liquids



H. KoPPERs 2.249.009

APPARATUS FOR THE DISTILLATION OF HIGH-BOILING LIQUIDS y 'July 15, 1941.

Filed Feb. 15, 1939 Patented July 15, 1941 FFICE APPARArUs Fon 'run ms'rlLLA'rIoN or HIGH-Bommcluoums Heinrich Koppers, Essen, Germany,assign'or, by mesne assignments, to Koppers Company,

Pittsburgh,

Pa., a. corporation of Delaware 2 Claims. (Cl. 202-215) i The ,invention ,relates to the distillation of highboiling substances such as coal tar pitch.

High boiling substances as for instance bituminous coal tar pitch, residues of mineral oil treatment, or residues of coal hydrogenation, are distilled in order to produce valuable oils, or a solid residue such as pitch coke. 'I'he high boiling substances of the kind mentioned show a tendency to decompose during the distillation and form solid matters. Therefore it -is disad- -vantageous to treat them in distllling vessels usual for distilling low boiling substances, such vessels being normally heated up from outside. Ceramic chambers are out ofthe question in this connection as it is to be feared that the distillation products areA unnecessarily overheated. Furthermore, ceramic chambers easily become very leaky. At a high temperature the pitchand similar matters become as fluid as Water. If the liquid pitch enters the brick joints it car- ,bonizes there, undergoing expansion while doing so and -destroys the chamber walls, which are built uprof single bricks.

I have found that the distillation of pitch may be effected by passinghot, preferably nonoxidizing gases through the mass during the distillation. 'Ihe distillates separate very easily from the vapours or gases later when cooling means of a grab or the like. The lid of the vesysel is strongly lined with refractory material for the purpose of insulating it. The rim of the lid extends into a collar of the lower part of the vescarried forward until coke is formed the heat-- ing is eiiected as from the outside as well as by passing hot gases inside. After the mass has down. On the other hand the hot jgases are cooled-down in passing through the pitch and thus the distilling products are protected against being overheated.

Now, according to my invention, an apparatus for the distillation of pitch and similar matters is provided which is of such a design that combustion products of high temperature are driven through the mass, the apparatus for the distillation comprising substantiallyV two parts, the upper ypart of which, together with a dip pipe, being designed so as to be lifted, after .loosening the anges serving for the connection with the combustion chamber and gas collecting main respectively. If one distils until a solid residue is obtained, this residue may be discharged from the container by a 'suitable grab.v

The distilling vessel may consist'of steel and is installed in such a way that the bottom and the sides can be heated up. This heating from outside is applied until a solid residue is obtained and the residue (coke) loosens itself from the walls of the vessel. 'At temperatures below dull red heat the mass sticks to the metal Wall; at temperatures slightly` above dull red heat, however, it loosens itself and becomes free so that the solid mass may be discharged by been evaporated to dryness the passing of hot combustion gases through the interior of the vessel is stopped and thevresidue is directly cooled in the vessel by spraying water thereover. Then the lid of .the-vessel is lifted and Ithe vessel is emptied by means of a grab. Thev dip pipe may be providedwith lhooks'protruding from the side of same and in this case the solid matter formed rthus may be easily discharged from the vessel bylifting the diprpipe from which the coke may be removed outside the apparatus.

If pitch coke is to be produced from bituminous coal tar for use for electrodes one may apply various methods.

One may distill thetar in the vessel, for instance, until a hard pitch with.a softening point of about C. is formed. This hard Ditch then may be charged in aliquid state into a hot coke oven. However, it is also possible to distill in the vessel until a hard pitch with a` softening point of about 200 to 220 C. is recovered. 'I'hen this material is solidified by running over a suitable cooler such asa cooling conveyor. The cold solid.y material then may be charged into a coke oven in the manner well known in coke oven practice. terial becomes fluid again and carbonizes .and a coke cake is nally formed Vwhich may be pushed out in the usual manner.

If the material is distilled in the apparatus designed according to .the invention until car- -bonization to coke takes place in the vessel, it is not possible to drive out volatile matters from the product later in. a horizontal chamber oven. In this case the material which has been discharged by the grab has to be crushed and then In theV coke oven the madegasiiled, preferably in a continuously operated vertical chamber which is heated up from outside likea vertical chamber or retort oven used in gas works.

'I'he distillation by hot gases with direct contact of the hot gases with the distilllng material has the great advantage that the distilling products are protected against undue decomposition. A further advantage consists iny -the fact that the heating of the vessel from outside need not take place as long as liquid products exist in the distilllng vessel. The outer heating is only used if one wants to loosen the solid product from the metal walls of the vessel. According to my experience, difficulties occur only if the vessel is heated from outside, as deposits are formed during the distillation of the liquid matter on the walls, which'prevent the heat from being transmitted into the charge: thus the vessel walls may be overheated andl be destroyed.

With the above and other objects and fea- 'tures of my present invention in view I shall now describe a preferred embodiment thereof .on the lines of the accompanying drawing For instance the process may be carried out in the following manner. 'I'he content of the vessel is at first mainly heated up by hot gases coming from the combustion chamber I8 the heating by the heating flues 3 and 4 only startswhenthe vessel content is about to solidify. As soon as the content has become solid' the heating by means of the gases from the combustion chamber I8 may be stopped or reduced. The heating by means of the ilues `3 and 4 is continued for some time until the solidiiled charge contracts and leaves the metal wall of the vessel I. This generally takes place when the metal body of the vessel is heated up to dull red heat.

After the mailling process is crushed the residue, if it is still liquid, may be discharged i by means of a slphon or in any other suitable manner.

. The distilling vessel is marked I. It consists preferably of steel and has the form of a bucket open at the top. The vessel I tapers towards its bottom in order to facilitate discharging.

The distilling vessel Il is surrounded by refractory brick work 2. Below the vessel a heating flue 3 is provided. Within the range of the side walls of the vessel the heating flues 4 are installed. The brickwork 2 is held together by an anchorage 5.

At the upper rim of the vessel I a water seal 6 is provided into which extends the rim 1 of the vessel lid 8. 'I'he vessel lid 8 is Alined with a suitable heat insulating material.

On the outside of the lid 8 ears III are provided in which hooks II of a travelling crane I2 may engage. -By means of this crane the lid of the vessel lid 8 may be lifted.

In the center of the vessel lid 8 an opening is arranged through which a brick-lined pipe I3 extends. The pipe I3 dipsinto the material to be treated in the vessel I (for instance bituminous coal tar pitch). From the dip pipe I3 a pipe I4 which is also brick-lined leads over a flange connection I6 tted with a compensation installation |5 to a waste gas pipe I1 of a combustion apparatus I8 preferably consisting of a chamber built in refractory material. By means of a blower 2I air and combustion gas is introduced under pressure through pipe lines I9 and 20 into the combustion apparatus I 8. The media burn in chamber I8 and pass through the brick lined pipes I4 and I1 into the dip pipe I3. From there they pass through the material to be treated inside the distilllng vessel.

During the passage through the distillng material the hot gasses give-oil' their heat. The cooled down gases together with the distillation vapours escape through the off-take 22 extending from the vessel lid 8. The vapours and gases are drawn off to a cooler connected with a suitable container for the condensate.

The heating tlues 3 and 4 are equipped with suitable burners, which are not shown on the drawing for' simplicitys sake. 'I'he heating flues are preferably used ln order to vaporize the' volatile content of the vessel until coke is formed.

When the vessel content is solid the vessel lid 8 is lifted by means of the crane I2. 'I'he hooks 23 provided on the dip-pipe I3 take the solid residue with them. The dip pipe I8 and the hooks 23 can then be freed from the coke by knocking the coke off, or by another suitable method.

In order to disconnect the pipe I4, the compensator I5 is slightly compressed by means of a lever 24, or in another way, so that the flanges I6 may move away from one another so far that the pipe I4 is clear off the pipe I1. In order to connect the pipes 4 and I1 again in a gas-tight manner the compensator is brought again in the initial position and the flange connection is closed.`

In a similar way a flange connection is provided at 25 for the pipe 22 of the vessel lid 8.

The crane I2 travels on the framework 28. Several distilllng vessels are suitably arranged together so that one single crane I2 may be used for operating each of several apparatus in a battery. l

' From pipe I1 branches-off an oif-take 21 which is connected to the open air and can be shut on therefrom. Through this pipe 21 combustion gases from chamber I8 may be removed if necessary and when gases are not to be passed through dip pipe I3.

As may be seen from the above, the hot gases from the combustion chamber I8 are led under increased pressure into the liquid which is contained in the vessel I. Additional means may be provided 'to maintain an increased pressure inside the combustion apparatus during the distillation, and for instance, the free section of the pipes connecting the combustion chamber with the distilllng apparatus may be varied. This is of advantage as the combustion is complete in the chamber I8 owing to the increased pressure and therefore little carbon monoxide is contained in the hot gases.` In consequence the material in the distilllng vessel is prevented from being oxidized. It is also possible to connect a vacuum pump to .the olf-take 22 of the vessel lid 8, or to the condensating device which is connected with the lid 8, in order to maintain a reduced pressure in the vessel I, which allows a distillation of the tarry constituents without decomposition. In this case it is possible to suck the gases from the combustion chamber I8 through the material in the vessel I.

The sealing device 6, 1 is suitably lled continuously withV water, or another suitable sealing liquor, so that a vaporisation does not take place in the sealing device. Instead of a water seal the connection between the vessel I and the lid 8 can be sealed by means of an asbestos cord impregnated with tar, or in another suitable way.

I have now described my present invention on the lines of a preferred embodiment thereof but my invention is not limited in all its aspects to the mode of carrying it out as described and shown, since the invention may be variously embodied within the scope of the following claims.

I claim:

1. Apparatus for the distillation of high boiling substances such as coal tar pitch, residues of mineral oil treatment or residues of the coal hydrogenation and the like, by means of hot gases passed through the material to be treated comprising a bucket like vessel surrounded by refractory material and open at the top, means for heating said vessel from outside, a separately removable cover adapted to close said vessel, said cover having a pipe like projection on its lower side, said pipe like projection being open at its lower end and bengfdesigned so as to pass hot gases through the material to be treated in said vessel, said pipe like projection being con- 'nected on the upper side of the cover with means arranged outside said vessel and adapted to produce hot gases, said cover further being provided with an outlet-l adapted to' draw-olf distillation products such as gases and vapours out of said vessel and means for moving hot gases through said vessel connected to the hot gas producing means, the pipe like projection arranged on the lower side of the cover being provided with hook-like extensions protruding sidewards to extract coke when the cover and pipe like projection are withdrawn fromV the vessel.

2. Apparatus as claimed in claim 1 wherein between the distilling vessel and the removable HEINRICH KOPPERS. 

